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Mucous Cyst

Divya Singh, MD, Hand and Orthopedic Surgeon, Department of Orthopedic Surgery, Group Health Permanente
A Lee Osterman, MD, Director of Hand Surgery Fellowship, Director, Philadelphia Hand Center; Director, Professor, Department of Orthopedic Surgery, Division of Hand Surgery, University Hospital, Thomas Jefferson University

Updated: Feb 5, 2008

Introduction

Mucous cysts (see Image 1) are ganglions of the distal interphalangeal joint (DIP) of the hand or of the toes. They have had several names, including mucoid cysts, synovial cysts, myxoid cysts, and myxomatous cutaneous cysts.[1,2,3,4,5,6,7,8 ]

History of the Procedure

Treatment options in the past have included aspiration, electrocautery, chemical cautery, steroid injection, and various types of surgical excision. Surgery currently is considered the definitive treatment for mucous cysts.

Problem

Apart from the cosmetic deformity, patients with mucous cysts may note chronic drainage, infection,[9 ]and pain. The pain may be secondary to the arthritic joint, as well as to the cyst itself.

Frequency

Mucous cysts are most common in the fifth through seventh decades of life. Mucous cysts are more common in women, who constitute roughly 70% of the patients.

Etiology

The precise etiology of mucous cysts is unclear; theories include synovial herniation, extensor retinacular metaplasia, myxomatous degeneration, and excess hyaluronic production by fibroblasts.

Pathophysiology

Mucous cysts are associated with degenerative joint disease of the DIP joint (see Image 2) in 60-80% of cases. Studies have shown a pedicle between the cyst and the DIP joint capsule.[10,11,12 ]

(See also the Medscape topic Rheumatoid Arthritis.)

Presentation

On physical examination, the cyst is located between the DIP extensor crease and the eponychium, lateral to the midline, measuring up to 15 mm (averaging 7 mm). The overlying skin can be thick or thin, and the patient may report sporadic drainage of the viscous fluid. Some erythema may surround the ganglion. Eventually, the cyst may result in a grooved deformity of the nailbed, or a nail groove may be present before the cyst is visible. Patients present to their physicians because of the deformity, although some may complain of discomfort.[13,14,15,10,12,16 ]

Differential diagnoses include Heberden nodes or rheumatoid nodules, epidermoid inclusion cyst, Dupuytren knuckle pad, xanthoma, giant cell tumor of the tendon sheath, and gout.

Indications

Surgical excision is indicated in the presence of active infection, drainage, or pain. Patients also may complain of nailbed deformity or extensor lag.

Relevant Anatomy

See Surgical therapy.

Contraindications

There are few contraindications to surgery. Even if the patient has medical comorbidities with concomitant risks with anesthesia, surgery can be performed with a digital block.

Workup

Imaging Studies

  • Radiographs may show changes typical of degenerative arthritis, such as joint space narrowing, subchondral sclerosis, and dorsal osteophytes (see Image 3).
  • Additional studies rarely are needed. The diagnosis usually is made clinically, although an MRI can help in difficult cases.

Histologic Findings

Grossly, mucous cysts are cystic, smooth, translucent masses with viscous fluid. Histologically, under light and scanning microscopy, mucous cysts share the same ultrastructure as other soft-tissue ganglions. Under light microscopy, ganglions have a smooth collagenous lining. Using scanning electron microscopy, crisscrossing layers of collagen are identified, with areas of elevations hypothesized to be multifunctional mesenchymal cells. No major degenerative or inflammatory changes are seen, nor are bursal or synovial endothelial cells. Multiple cavities may be found coalescing into a larger space.

Treatment

Medical Therapy

Treatment options in the past have included aspiration, electrocautery, chemical cautery, steroid injection, and various types of surgical excision. Most of these procedures are associated with significant recurrence rates, although these tend to be lower than those of carpal ganglions. Aspiration of digital ganglions was found to have a 65-69% success rate, compared with 27-45% for carpal ganglions. One caveat with aspiration is the risk of infection. In fact, infections of the cyst and subsequently the joint can occur from spontaneous breakdown of the cyst or from iatrogenic aspiration. Promptly treat such infections, as they often lead to septic arthritis and osteomyelitis with disastrous complications. Some early authors proposed that low-voltage radiation is associated with a lower recurrence rate than surgery.[17,18,19,20,21,22 ]

Surgical Therapy

Surgery currently is considered the definitive treatment for mucous cysts. Surgery is recommended in the presence of ongoing pain, recurrent infection, or chronic drainage. Based on surgeon's preference and locations of the cyst, various surgical incisions can be used, including an H, T, U, or a transverse curving incision shape. After the skin is incised, the dissection is continued around the cyst, tracing the stalk down to the joint. Care must be taken to avoid damaging the terminal extensor tendon, germinal matrix, and the terminal portions of the neurovascular bundles. Depending on the intraoperative findings, a synovectomy, osteophyte resection, and debridement may be performed. A disrupted terminal extensor tendon (whether iatrogenic or cyst related) should be repaired to prevent subsequent extensor lag.[8,18,20,23,24,25,26 ]

In the event of significant DIP joint arthritis and pain, an arthrodesis can be performed at the same surgery. Chen advocated radical excision of the attenuating skin overlying the cyst, as this can contain satellite ducts and lakes of mucoid degeneration. The surgeon can obtain the patient's consent preoperatively for a skin graft if skin excision leaves extensor tendon or joint exposed. Rotation flaps have been utilized to compensate for excised or thinned skin overlying the cyst. The decision to use skin graft, a rotational flap, or close primarily is largely surgeon dependent. In the authors' experience, most incisions can be closed primarily without the need for further coverage procedures.[27,28,29 ]

Preoperative Details

Preoperative planning is limited, as much of the procedure is based on intraoperative findings. In the presence of significant arthritic pain, the patient consent can be obtained for a DIP joint arthrodesis. This can be done with single screw fixation (eg, an Acutrak or Herbert screw) or with Kirschner wires (K-wires) and cables, based on surgeon's preference.

The relevant factors to remember preoperatively are to remove the osteophyte and obtain adequate skin coverage postexcision. Patient consent should be obtained for skin graft or rotation flap if needed.

Intraoperative Details

Studies have shown the necessity of excising not only the cyst, but also the underlying DIP osteophyte. The recurrence rate with both cyst and osteophyte excision is 3-12%, compared to a 25-50% recurrence rate with cyst excision alone. Care must be taken to avoid injury to the germinal matrix and to prevent further nail deformity. One study described treatment of fingernail deformities secondary to mucous cysts with removal of the osteophyte only, without excision of the ganglion or skin. In this study of 20 ganglion cysts, the ganglion did not recur in any patients and 2 nails had residual grooves.

Postoperative Details

Unless an extensor tendon repair or some other procedure requiring joint immobilization is involved, only a light dressing is needed postoperatively. Gentle active range of motion is allowed, and sutures usually are removed after 2 weeks.

Complications

Infection is a common complication of mucous cysts, either preoperatively or postoperatively. For that reason, prophylactic antibiotics are used intraoperatively and for 3 days postoperatively.[30,9 ]

Complications from surgery include extensor tendon disruption, recurrence, and nail deformity from injury to the germinal matrix. Other potential risks include persistent pain, swelling, stiffness, and infection. If a patient continues to have pain secondary to degenerative joint disease, a DIP joint arthrodesis may be performed later.

Outcome and Prognosis

The recurrence rate with both cyst and osteophyte excision is 3-12%, compared with a 25-50% recurrence rate with cyst excision alone.

Future and Controversies

Studies have shown the necessity of excising not only the cyst, but also the underlying DIP osteophyte (see Intraoperative details).

Multimedia

Mucous cyst, lateral to the midline, with thinned...

Media file 1: Mucous cyst, lateral to the midline, with thinned skin. One possible surgical incision is indicated.

Degenerative changes at the distal interphalangea...

Media file 2: Degenerative changes at the distal interphalangeal joint.

Dorsal osteophyte seen at the distal interphalang...

Media file 3: Dorsal osteophyte seen at the distal interphalangeal joint.

References

  1. Arner O, Lindholm A, Romanus R. Mucous cysts of the fingers, report of 26 cases. Acta Chir Scand. 1956;111:314-321.

  2. Bourns HK, Sanerkin NG. Mucoid lesions ("mucoid cysts") of the fingers and toes. Clinical features and pathogenesis. Br J Surg. 1963;50:860-66.

  3. Constant E, Royer JR, Pollard RJ. Mucous cysts of the fingers. Plast Reconstr Surg. Mar 1969;43(3):241-6. [Medline].

  4. King ESJ. Mucous cysts of the fingers. Aust N Z J Surg. 1951;21:121-29.

  5. Nelson CL, Sawmiller S, Phalen GS. Ganglions of the wrist and hand. J Bone Joint Surg Am. Oct 1972;54(7):1459-64. [Medline].

  6. Thornburg LE. Ganglions of the hand and wrist. J Am Acad Orthop Surg. Jul-Aug 1999;7(4):231-8. [Medline].

  7. Kivanc-Altunay I, Kumbasar E, Gokdemir G, Koslu A, Tekkesin M, Basak T. Unusual localization of multiple myxoid (mucous) cysts of toes. Dermatol Online J. 2004;10(1):23. [Medline].

  8. Schmoeckel C, von Mallinckrodt G, Risch M. [Dorsal mucoid cyst--ganglion-like pseudocyst of the joint space]. Hautarzt. Sep 2000;51(9):682-4. [Medline].

  9. Rangarathnam CS, Linscheid RL. Infected mucous cyst of the finger. J Hand Surg [Am]. Mar 1984;9(2):245-7. [Medline].

  10. Loder RT, Robinson JH, Jackson WT. A surface ultrastructure study of ganglia and digital mucous cysts. J Hand Surg [Am]. Sep 1988;13(5):758-62. [Medline].

  11. Newmeyer WL, Kilgore ES Jr, Graham WP 3rd. Mucous cysts: the dorsal distal interphalangeal joint ganglion. Plast Reconstr Surg. Mar 1974;53(3):313-5. [Medline].

  12. Psaila JV, Mansel RE. The surface ultrastructure of ganglia. J Bone Joint Surg Br. May 1978;60-B(2):228-33. [Medline].

  13. Barth J, Heinisch G. Multiple black nodules on the thumb. Dorsal mucoid cysts of the finger. Arch Dermatol. May 1993;129(5):633-4, 637. [Medline].

  14. Brown RE, Zook EG, Russell RC. Fingernail deformities secondary to ganglions of the distal interphalangeal joint (mucous cysts). Plast Reconstr Surg. Apr 1991;87(4):718-25. [Medline].

  15. Johnson WC, Graham JH, Helwig EB. Cutaneous myxoid cyst. A clinocopathological and histochemical study. JAMA. 1965;191:15-20.

  16. Smith EB, Skipworth GB, VanderPloeg DE. Longitudinal grooving of nails due to synovial cysts. Arch Derm. 1964;89:364-366.

  17. Fisher RH. Conservative treatment of mucous cysts. Clin Orthop. 1974;0(103):88. [Medline].

  18. Gingrass MK, Brown RE, Zook EG. Treatment of fingernail deformities secondary to ganglions of the distal interphalangeal joint. J Hand Surg [Am]. May 1995;20(3):502-5. [Medline].

  19. Jacox HW, Freedman LJ. The roentgen treatment of myxomatous cutaneous cysts. Radiology. 1941;36:695-699.

  20. Kleinert HE, Kutz JE, Fishman JH. Etiology and treatment of the so-called mucous cyst of the finger. J Bone Joint Surg Am. Oct 1972;54(7):1455-8. [Medline].

  21. Korman J, Pearl R, Hentz VR. Efficacy of immobilization following aspiration of carpal and digital ganglions. J Hand Surg [Am]. Nov 1992;17(6):1097-9. [Medline].

  22. Richman JA, Gelberman RH, Engber WD. Ganglions of the wrist and digits: results of treatment by aspiration and cyst wall puncture. J Hand Surg [Am]. Nov 1987;12(6):1041-3. [Medline].

  23. Chen WS, Lin CC. Mucous cyst of the distal interphalangeal joint: treatment by simple excision or excision and rotation flap. J Hand Surg [Br]. Feb 1991;16(1):118-9. [Medline].

  24. Crawford RJ, Gupta A, Risitano G. Mucous cyst of the distal interphalangeal joint: treatment by simple excision or excision and rotation flap. J Hand Surg [Br]. Feb 1990;15(1):113-4. [Medline].

  25. Eaton RG, Dobranski AI, Littler JW. Marginal osteophyte excision in treatment of mucous cysts. J Bone Joint Surg Am. Apr 1973;55(3):570-4. [Medline].

  26. Kasdan ML, Stallings SP, Leis VM. Outcome of surgically treated mucous cysts of the hand. J Hand Surg [Am]. May 1994;19(3):504-7. [Medline].

  27. Imran D, Koukkou C, Bainbridge LC. The rhomboid flap: a simple technique to cover the skin defect produced by excision of a mucous cyst of a digit. J Bone Joint Surg Br. Aug 2003;85(6):860-2. [Medline].

  28. Shin EK, Jupiter JB. Flap advancement coverage after excision of large mucous cysts. Tech Hand Up Extrem Surg. Jun 2007;11(2):159-62. [Medline].

  29. Blume PA, Moore JC, Novicki DC. Digital mucoid cyst excision by using the bilobed flap technique and arthroplastic resection. J Foot Ankle Surg. Jan-Feb 2005;44(1):44-8. [Medline].

  30. Fritz GR, Stern PJ, Dickey M. Complications following mucous cyst excision. J Hand Surg [Br]. Apr 1997;22(2):222-5. [Medline].

Keywords

mucoid cyst, synovial cyst, myxoid cyst, myxomatous cutaneous cyst

Contributor Information and Disclosures

Author

Divya Singh, MD, Hand and Orthopedic Surgeon, Department of Orthopedic Surgery, Group Health Permanente
Divya Singh, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons
Disclosure: Nothing to disclose.

Coauthor(s)

A Lee Osterman, MD, Director of Hand Surgery Fellowship, Director, Philadelphia Hand Center; Director, Professor, Department of Orthopedic Surgery, Division of Hand Surgery, University Hospital, Thomas Jefferson University
Disclosure: Nothing to disclose.

Medical Editor

Miguel A Schmitz, MD, Consulting Surgeon, Department of Orthopedics, Klamath Orthopedic and Sports Medicine Clinic
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Sean P Scully, MD, PhD, Professor, Department of Orthopedics, University of Miami
Sean P Scully, MD, PhD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, International Society on Thrombosis and Haemostasis, and Society of Surgical Oncology
Disclosure: Nothing to disclose.

CME Editor

Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital
Dinesh Patel, MD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Association of Physicians of Indian Origin, American College of International Physicians, and American College of Surgeons
Disclosure: Nothing to disclose.

Chief Editor

Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine
Harris Gellman, MD is a member of the following medical societies: American Academy of Medical Acupuncture, American Academy of Orthopaedic Surgeons, American Orthopaedic Association, American Society for Surgery of the Hand, and Arkansas Medical Society
Disclosure: Nothing to disclose.

Further Reading

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